You often hear people say - cut the carbs as they turn to fat, but does that really happen and does a low carb diet mean you burn more fat?
In this blog post we'll have a look at how your body decides whether to store or use the energy you get from food, and which fuel source it prefers - carbs, fat or protein.
Let me explain how this all works.
When you exercise your body can choose its energy source. What the body does is first consider how much energy it gets from a fuel sources vs. how much energy it would cost it to store it instead and use an alternative fuel source.
Carbs provide 4 calories of energy per gram consumed. It costs the body 7% of this to store as glycogen, but a whopping 23% to store it as fat. It will therefore always choose to store carbs as glycogen rather than fat where possible. Glycogen can provide energy very quickly – in seconds, so is your body’s first choice for energy when you start moving.
Once your glycogen stores are depleted (which takes about an hour) your body will then look to either break down protein (ie your lean muscle) or fat for energy.
Protein provides 4 calories per gram and is the next choice for the body as a fuel source. This is because, of all the three macronutrients, it costs the body the MOST energy to store as fat – 26% in fact. Your body would rather use it to build muscle so give it a helping hand with some resistance training!
Protein is not as quickly available as glycogen either. It takes time and energy to metabolize it, more so than the other macronutrients. This is called the thermic effect of food and is another reason why eating protein can help with a fat burning fitness goal. It is also why it comes in second place to glycogen for the body when needing energy to workout.
Fat provides 9 calories per gram consumed and costs the body only 3% of that to store as fat. So when you consume a meal the body will always store the fat as fat first and aim to use the other two macronutrients (protein and carbs) as your energy supply. It’s just more economical.
From this, you start to understand why fat loss can be challenging and why manipulation of the macronutrients plays a key role in how successful you are, along with the style of training you undertake. The bottom line is – to build a lean, strong body you must include resistance training, eat enough protein and ensure your overall calorie intake matches your energy needs.
A note on alcohol
When a toxin enters the body, your body’s first priority is to get rid of it. Alcohol provides 7 calories per gram (nearly twice that of carbs!). The body has no means of storing a toxin, so the energy the alcohol provides is used in preference to all other macronutrients. This means that when you consume alcohol…you won’t burn ANY fat at all until ALL the alcohol has been cleared.